From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932737AbbFQWZz (ORCPT ); Wed, 17 Jun 2015 18:25:55 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34920 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757522AbbFQWZo (ORCPT ); Wed, 17 Jun 2015 18:25:44 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eryu Guan , "Theodore Ts'o" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 065/146] ext4: check for zero length extent explicitly Date: Wed, 17 Jun 2015 15:22:50 -0700 Message-Id: <1434579851-1719-66-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1434579851-1719-1-git-send-email-kamal@canonical.com> References: <1434579851-1719-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Eryu Guan commit 2f974865ffdfe7b9f46a9940836c8b167342563d upstream. The following commit introduced a bug when checking for zero length extent 5946d08 ext4: check for overlapping extents in ext4_valid_extent_entries() Zero length extent could pass the check if lblock is zero. Adding the explicit check for zero length back. Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o Signed-off-by: Kamal Mostafa --- fs/ext4/extents.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 30dee3c..410841e 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -377,7 +377,7 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); ext4_lblk_t last = lblock + len - 1; - if (lblock > last) + if (len == 0 || lblock > last) return 0; return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); } -- 1.9.1